Iambic keying: How to?

Stumbled across interesting YouTube video on "Iambic Keyer and Technique" attempting to teach how to use an Iambic keyer. It's about 5 1/2 mins long. Another video from IK0YGJ simply shows the sender using a beautiful Begali Sculpture and sending at 50wpm.
While I'm at it I should include the link to the 9mins plus video explaining how to use iDitDahText on the iphone.